Couple years ago was not so tough
Two years ago I lived in Sub-saharan Africa and I could get lots of film using postage stamps...127, Kodapak, 4x5, etc. One old guy at a photo processing shop called his younger employees around to give them a lecture on the film from my Solaris 126 cartridge...they'd never seen such perforations.
There was even Tura film available from a place in an industrial park who would send me an order (Didn't much like the film though)
Also lots of expired film in refridgerators. A coleague and I bought hundreds of boxes of 120 Neopan SS dated best before 1993 until it was all gone. The stuff was fantastic.
Now I'm in Ontario, and I see there are new brands of 126 and 127 available that weren't around 2 years ago. I also play with polaroid 4x5 when I feel rich...I didn't know it was still around. Not that I don't acknowledge an availability problem, but there are still lots of emulsions and formats that I've yet to get around to.